1. Field of the Invention
This invention relates generally to an apparatus for adjustably supporting a cutting tool or the like and particularly relates to an adjustable four bar linkage mounted on a linear bearing for supporting a cutting tool.
2. Description of Prior Developments
Assemblies and mechanisms for supporting and/or guiding various cutting tools though their operative movements have been known and used for many years. In the tile and ceramic trades tile cutting tools have frequently used a rotary saw to produce the cuts required to properly size and fit the tiles within a desired pattern. A common design mounted the saw in a fixed position above a cutting table over which a roller carriage would reciprocate. The path of the carriage was fixed by guide rails fixed to the cutting table so that the carriage rollers would follow the fixed track.
In order to cut a tile using such an apparatus it was necessary to align a tile on the carriage and push the carriage along the track beneath the saw so that the tile passed through the path of the rotating saw blade. While this arrangement was suitable for single straight cuts, more complicated cuts required the use of assorted attachments. Moreover, plunge cuts and compound angle cuts were often not possible using prior cutting assemblies.
One approach to making plunge cuts relied upon mounting the saw on the end of a pivotable arm. As the arm rotated about an arc the blade could be plunged into the surface of a tile. This approach produced less than perfect results since the cutting edge of the rotating blade was constrained to define an arcuate cutting path through the tile as the angle of the blade varied from a perpendicular alignment with the tile to a skewed orientation. This resulted in somewhat ragged and curved edges along the plunge cut surface where smooth and flat edges were desired. Moreover, by making an arcuate cut instead of a straight or vertical cut, blade life was decreased due to greater amounts of tile material being cut than in the case of a simple straight cut. Transverse or axial stressing of the blade often accompanied arcuate plunge cutting and resulted in blade damage.
Another drawback associated with prior tile cutting apparatus is the difficulty encountered when producing a compound angle cut. Such a cut would require two separate strokes. That is, one stroke is required for making a cut at a bias to the edge of the tile and a second for cutting a bevel along the edge of the bias cut. This method was generally inconvenient, time consuming and unsuitable for high volume production.
Prior cutting devices have relied upon a heavy cumbersome framework having a relatively complex and cluttered structure for supporting and guiding a cutter blade during cutting operations. Such devices often restricted the ability of the operator to satisfactorily perform cutting operations on large tiles due to interference of the tiles with the framework.
Accordingly, a need has arisen for a lightweight cutting apparatus having a simple, uncluttered design which allows for the simultaneous cutting of bevels and angles in a workpiece during a single operative cutting stroke. A need also exists for a compact inexpensive portable cutting apparatus having an open design which facilitates the cutting of relatively large workpieces. A further need exists for a tile cutting apparatus capable of making a compound angle cut with a single stroke without the use of special attachments. Another need exists for a tile cutter capable of making smooth edged vertical plunge cuts in a simple and convenient manner without applying an axial load to a rotary cutting blade.